The present invention relates to a hidden lock for a jewelry or treasure box which is provided with a flexible metal wire having an end projected from an opening disposed at the bottom of the front side of a lower case of the box and a lock plate secured to the inner surface of front side of a cover case of the box. An M shaped recess disposed on the lock plate is able to be engaged with the projected end of the metal wire when the cover case is closed. The M shaped recess having three turnings is designed to have an increasingly raised and abruptly dropped surface before each turning thereof so to form a hooked stop thereat whereby the projected end of the metal wire is slidably guided in the recess and retained in place at each turning and can be limited to travel forward only. As the cover case is pushed downward, the projected end of the flexible metal wire is forced again to slide forward and is disengaged with the recess so as to permit the cover case to pop opened as a result of the actuation of a pair of spring biased hinges which couples the lower case to the cover case of the box.
There are many types of jewelry or treasure box designed in a fascinating and appealing manner so as to match with the luxury of the jewellery received therein. Most of the boxes are provided with a hidden lock in consideration of the integral beauty of the box.